Papers by Keyword: Ductility

Abstract: The implementation of glass in various industries may cause some problems due to its brittleness characteristic. Its usage in the transportation sector has led to death and serious injuries to drivers and passengers in vehicles. It shows that the manufacturing process of the materials used requires an improvement in terms of brittleness to provide better protection to the consumer. Therefore, rubber toughened PMMA (RT-PMMA) was introduced as the rubber has the ability to increase the ductility of PMMA. PMMA and two different grades of RT-PMMA namely RT-PMMA65 and RT-PMMA100 were taken into consideration to investigate the effect of different rubber contents on the ductility of PMMA. Other than strain rate and temperature, humidity is also one of the factors that affect the ductile properties of PMMA. In this study, tensile tests at different humidity levels (11% and 98%) will be carried out by immersing the specimens in two different solutions which are lithium chloride (LiCl) and potassium sulfate (K₂SO₄) beforehand. The output from the experimental works proved that the tensile properties of RT-PMMA are affected by the presence of humidity for all three grades of PMMA under consideration. It is also proved that RT-PMMA100 is more ductile compared to RT-PMMA65 on the tensile test.

Abstract: The flexural behavior of Incinerated Bio-Medical Waste Ash (IBWA) – Ground Granulated Blast Furnace Slag (GGBS) based Reinforced Geopolymer Concrete (RGPC) beams with Waste Glass Powder (WGP) as fine aggregate is explored in this research. The fine aggregate (M-Sand) is substituted by varying the waste glass powder as 0 percent, 5 percent, 10 percent, 15 percent, 20 percent, 25 percent, 30 percent, 35 percent, 40 percent, 45 percent, and 50 percent, and the mixture is cured under atmospheric curing. The impact of the WGP weight percentage on the flexural behavior of GPC beams is analyzed. The conduct of RGPC beams varies from that of ordinary Portland Concrete (OPC) beams, which is defined and examined. Deflection, ductility factor, flexural strength, and toughness index were measured as flexural properties for beams. In contrast to the reference beams, the RGPC beams containing 50% Waste Glass Powder as fine aggregate demonstrated a major increase in cracking resistance, serviceability, and ductility, according to the experimental finding. The RGPC beam without WGP ended in failure with a brittle manner whereas those beams with WGP encountered ductile failure. The RGPC beams' load ability improved by up to 50% as the weight percentage of WGP was enhanced.

Abstract: On the demand of reducing the global warming due to cement production which is used as main constituent in the production of concrete and minimizing the environmental impact caused by the waste and its disposal methods, this study was aimed. This study looked in to detail insight view on effective utilization of waste wood ash in the production of geopolymer concrete beams and columns to alternate the conventional reinforced concrete elements in construction industry. Waste wood ash is a waste by product produced in the nearby hotel and factories by burning the waste wood collected from timber industries and the ash are thrown in to land which creates a major environmental pollution. Geopolymer is a novel inorganic eco-friendly binding agent derived from alkaline solution that stimulates aluminosilicate source material (such as metakaolin, fly ash and GGBS). In this research, behaviour of beams in deflection, ductility factor, flexural strength and toughness index and columns in load carrying ability, stress strain behaviour and load-deflection behaviours were examined for three types of concretes (30% WWA – 70% Fly ash Geo-polymer concrete, Fly ash Geo-polymer concrete and Reinforced Cement Concrete). The results showed that inclusion of waste wood ash in geopolymer concrete helped in enhancing the load carrying capacity of beam and column by 42% and 28%. Further, the behaviour of structural elements in stiffness, ductility and toughness were also improved with the replacement of waste wood ash.

Abstract: This study aims to analyze the use of Incinerated Bio-Medical Waste Ash (IBWA) in reinforced concrete structural member with ground granulated blast furnace slag (GGBS) as an alternate building ingredient instead of cement. Biomedical waste was produced from various medical resources such as hospitals, medical institutes and research centres. GGBS is the waste generated from the steel plant. The climate is now being affected by the release of CO₂ (global warming) from the Portland cement industries. Therefore, greater attention must be paid to study efforts to use geopolymer concrete. Geopolymer is a novel inorganic eco-friendly binding agent derived from an alkaline solution that stimulates aluminosilicate source material (GGBS, Rice Husk Ash, Quartz Powder, metakaolin, fly ash and Silica Fume). In this research, laboratory tests for Reinforced Geopolymer Concrete (RGPC) beams (deflection, ductility factor, flexural strength and toughness index) and columns (load-carrying ability, stress-strain behaviour and load-deflection behaviour) were conducted for three types of proportions using [30% IBWA – 70% GGBS Geopolymer concrete, GGBS Geopolymer concrete and Reinforced Cement Concrete. The experimental findings revealed that the performance of reinforced 30% IBWA – 70% GGBS geo-polymer beams and columns worked more effectively than reinforced cement concrete beams and columns.

Abstract: The magnesium AZ31B alloy has been utilized in a variety of applications within the automotive and aviation industries due to its high specific strength, low-cost processing, and low density. However, the AZ31B alloy generally has poor ductility and limited workability at room temperature. The objective of this study was to develop a manufacturing processing technique to increase the potential uses of this alloy. The methodology includes cold rolling and annealing using small pass reductions until the samples reached a final thickness of 1.78 mm (0.07 in). The samples were cut into 10.16 mm (0.4 in), 7.62 mm (0.3 in), and 5.08 mm (0.2 in) thicknesses prior to cold rolling and were rolled in 0-, 45-, and 90-degree rolling directions. The grain shapes and sizes were examined via optical microscopy. Tensile testing was conducted to determine the strength and ductility. Scanning electron microscopy (SEM) images were taken to evaluate fractured surfaces. All processes including rolling direction and furnace cooling or air cooling after annealing produced similar results of medium strength (245-250 MPa in ultimate strength, 122-127 MPa in yield) and greater than 22.5% elongations in very thin sheets. Samples rolled along the 45-degree direction produced the highest percent reduction in thickness.

Abstract: Concrete members are reinforced by steel fibers to overcome their brittle nature. This paper is focused on the effect of percentage of fiber and the maximum aggregate size on mechanical properties of concrete samples such as compressive and tensile strengths, and ductility. The mean values of these quantities show that by increasing the reinforcement content to 0.66% and the size to 12.5 mm, there is a dramatic improvement on properties of samples. Also, they demonstrate that the size of coarse aggregate has more effect on improvement of the quantities in comparison to steel fiber content and changing the size and fiber content has more effects on ductility than mechanical properties. Statistical approach which considers standard deviations of experimental data, confirms that the gravel regardless of fiber content, leads to the highest improvement on properties with size of 12.5 mm. But the results show for volumetric steel fiber without considering aggregate size, is 0.33%. This clearly indicates the effect of data scattering on mean values of mechanical properties and ductility.

Abstract: The article deals with the problems of withstanding harsh temperatures by steel and iron. The authors of the work discuss iron denser high-temperature of γ modification and maximums and minimums of impact. In addition, the article analyses the transformations of iron and anomalies of properties: peak of heat capacity, acceleration of diffusion, etc. The authors take into account the consensus on the causes of polymorphism and the theoretical model of ferromagnetism. Besides, there is a consideration of "transformation" in interaction between Fe atoms that produce anomalies of steel properties. It is necessary to note the transformation detected by anomalies of any properties including mechanical. In the presented work the authors have made an attempt to prove transformations in iron at ~650 °C on the basis of extreme values of hardness and microhardness, metallographic structure, parameters of fine structure, precipitation resistance force depending on temperature. Therefore, the analysis of literature sources on physical and mechanical properties of iron and its derivatives has been made.

Abstract: Sustainability calls for reduction in the use of natural resources and man-made materials. In light of this, the present study demonstrates the potentials of the reduction of transverse reinforcement in structural walls. A structural wall 1.7 m long was designed following the Greek Code for Reinforced Concrete (GCRC). This wall was then constructed and tested under cyclic loading. The theoretical value of the uncracked stiffness was four times greater than the value calculated after the experiment. The wall was also designed according to the Compressive Force Path method (CFP), which allowed for a significant reduction in the transverse reinforcement for the same target values.

Abstract: Composite columns are generally installed in high-rise buildings and bridges. As well as being smaller and lighter than conventional reinforced concrete columns, composite columns offer high efficiency and ductility. In this research, experimental and analytical studies were carried out to investigate the optimal distribution of the ‎total steel area of the Concrete-Filled Hollow Steel Tube (CFHST) columns; the experimental program included 20 CFHST columns. ‎The main variables of the experimental study were the distribution of the total steel cross-sectional area over the internal concrete core (steel reinforcement) and the external steel tube, the cross-sectional shape, the width-to-breadth ratio t/b, and the presence or absence of shear connectors. In addition, using equations of different codes, comparison was conducted between the experimental and analytical results. For a constant steel cross-sectional area, the use of internal steel bars and external steel tubes, together with the use of shear connectors, was found to exhibit a better ultimate load capacity, stiffness, and ductility for the CFHST columns.

Abstract: The influence of thermal cycling treatment of pseudo-α-titanium alloys OT4 and VT20 on their structural and substructural characteristics, as well as their mechanical properties is considered. A significant change in structural characteristics is established. This contributes to an increase in the strength properties of alloys with satisfactory ductility and high-temperature strength.